linux/fs/xfs/scrub/dirtree_repair.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2023-2024 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <[email protected]>
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_trans_resv.h"
#include "xfs_trans_space.h"
#include "xfs_mount.h"
#include "xfs_log_format.h"
#include "xfs_trans.h"
#include "xfs_inode.h"
#include "xfs_icache.h"
#include "xfs_dir2.h"
#include "xfs_dir2_priv.h"
#include "xfs_attr.h"
#include "xfs_parent.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/bitmap.h"
#include "scrub/ino_bitmap.h"
#include "scrub/xfile.h"
#include "scrub/xfarray.h"
#include "scrub/xfblob.h"
#include "scrub/listxattr.h"
#include "scrub/trace.h"
#include "scrub/repair.h"
#include "scrub/orphanage.h"
#include "scrub/dirtree.h"
#include "scrub/readdir.h"

/*
 * Directory Tree Structure Repairs
 * ================================
 *
 * If we decide that the directory being scanned is participating in a
 * directory loop, the only change we can make is to remove directory entries
 * pointing down to @sc->ip.  If that leaves it with no parents, the directory
 * should be adopted by the orphanage.
 */

/* Set up to repair directory loops. */
int
xrep_setup_dirtree(
	struct xfs_scrub	*sc)
{ … }

/* Change the outcome of this path. */
static inline void
xrep_dirpath_set_outcome(
	struct xchk_dirtree		*dl,
	struct xchk_dirpath		*path,
	enum xchk_dirpath_outcome	outcome)
{ … }

/* Delete all paths. */
STATIC void
xrep_dirtree_delete_all_paths(
	struct xchk_dirtree		*dl,
	struct xchk_dirtree_outcomes	*oc)
{ … }

/* Since this is the surviving path, set the dotdot entry to this value. */
STATIC void
xrep_dirpath_retain_parent(
	struct xchk_dirtree		*dl,
	struct xchk_dirpath		*path)
{ … }

/* Find the one surviving path so we know how to set dotdot. */
STATIC void
xrep_dirtree_find_surviving_path(
	struct xchk_dirtree		*dl,
	struct xchk_dirtree_outcomes	*oc)
{ … }

/* Delete all paths except for the one good one. */
STATIC void
xrep_dirtree_keep_one_good_path(
	struct xchk_dirtree		*dl,
	struct xchk_dirtree_outcomes	*oc)
{ … }

/* Delete all paths except for one suspect one. */
STATIC void
xrep_dirtree_keep_one_suspect_path(
	struct xchk_dirtree		*dl,
	struct xchk_dirtree_outcomes	*oc)
{ … }

/*
 * Figure out what to do with the paths we tried to find.  Returns -EDEADLOCK
 * if the scan results have become stale.
 */
STATIC void
xrep_dirtree_decide_fate(
	struct xchk_dirtree		*dl,
	struct xchk_dirtree_outcomes	*oc)
{ … }

/*
 * Load the first step of this path into @step and @dl->xname/pptr
 * for later repair work.
 */
STATIC int
xrep_dirtree_prep_path(
	struct xchk_dirtree		*dl,
	struct xchk_dirpath		*path,
	struct xchk_dirpath_step	*step)
{ … }

/* Delete the VFS dentry for a removed child. */
STATIC int
xrep_dirtree_purge_dentry(
	struct xchk_dirtree	*dl,
	struct xfs_inode	*dp,
	const struct xfs_name	*name)
{ … }

/*
 * Prepare to delete a link by taking the IOLOCK of the parent and the child
 * (scrub target).  Caller must hold IOLOCK_EXCL on @sc->ip.  Returns 0 if we
 * took both locks, or a negative errno if we couldn't lock the parent in time.
 */
static inline int
xrep_dirtree_unlink_iolock(
	struct xfs_scrub	*sc,
	struct xfs_inode	*dp)
{ … }

/*
 * Remove a link from the directory tree and update the dcache.  Returns
 * -ESTALE if the scan data are now out of date.
 */
STATIC int
xrep_dirtree_unlink(
	struct xchk_dirtree		*dl,
	struct xfs_inode		*dp,
	struct xchk_dirpath		*path,
	struct xchk_dirpath_step	*step)
{ … }

/*
 * Delete a directory entry that points to this directory.  Returns -ESTALE
 * if the scan data are now out of date.
 */
STATIC int
xrep_dirtree_delete_path(
	struct xchk_dirtree		*dl,
	struct xchk_dirpath		*path)
{ … }

/* Add a new path to represent our in-progress adoption. */
STATIC int
xrep_dirtree_create_adoption_path(
	struct xchk_dirtree		*dl)
{ … }

/*
 * Prepare to move a file to the orphanage by taking the IOLOCK of the
 * orphanage and the child (scrub target).  Caller must hold IOLOCK_EXCL on
 * @sc->ip.  Returns 0 if we took both locks, or a negative errno if we
 * couldn't lock the orphanage in time.
 */
static inline int
xrep_dirtree_adopt_iolock(
	struct xfs_scrub	*sc)
{ … }

/*
 * Reattach this orphaned directory to the orphanage.  Do not call this with
 * any resources held.  Returns -ESTALE if the scan data have become out of
 * date.
 */
STATIC int
xrep_dirtree_adopt(
	struct xchk_dirtree		*dl)
{ … }

/*
 * This newly orphaned directory needs to be adopted by the orphanage.
 * Make this happen.
 */
STATIC int
xrep_dirtree_move_to_orphanage(
	struct xchk_dirtree		*dl)
{ … }

/*
 * Try to fix all the problems.  Returns -ESTALE if the scan data have become
 * out of date.
 */
STATIC int
xrep_dirtree_fix_problems(
	struct xchk_dirtree		*dl,
	struct xchk_dirtree_outcomes	*oc)
{ … }

/* Fix directory loops involving this directory. */
int
xrep_dirtree(
	struct xfs_scrub		*sc)
{ … }